Return DataVector directly from CPDF_CryptoHandler::EncryptContent()
Instead of making the EncryptContent() caller create the DataVector and
then passing it in as a span, move that work into EncryptContent()
itself. As a result, CPDF_CryptoHandler::EncryptGetSize() can become a
private method.
Also remove a conditional that always evaluates to true.
Change-Id: I24b48df1c6efe475ce80ed3c9c7512ee05ca5d35
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/121118
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Thomas Sepez <tsepez@google.com>
diff --git a/core/fpdfapi/parser/cpdf_crypto_handler.cpp b/core/fpdfapi/parser/cpdf_crypto_handler.cpp
index ea28bc2..70d4466 100644
--- a/core/fpdfapi/parser/cpdf_crypto_handler.cpp
+++ b/core/fpdfapi/parser/cpdf_crypto_handler.cpp
@@ -47,13 +47,15 @@
return type_obj && type_obj->GetString() == pdfium::form_fields::kSig;
}
-size_t CPDF_CryptoHandler::EncryptContent(uint32_t objnum,
- uint32_t gennum,
- pdfium::span<const uint8_t> source,
- pdfium::span<uint8_t> dest) const {
+DataVector<uint8_t> CPDF_CryptoHandler::EncryptContent(
+ uint32_t objnum,
+ uint32_t gennum,
+ pdfium::span<const uint8_t> source) const {
+ DataVector<uint8_t> dest(EncryptGetSize(source));
if (m_Cipher == Cipher::kNone) {
fxcrt::Copy(source, dest);
- return source.size();
+ dest.resize(source.size());
+ return dest;
}
uint8_t realkey[16];
size_t realkeylen = sizeof(realkey);
@@ -76,24 +78,24 @@
v = (uint8_t)rand();
}
CRYPT_AESSetIV(m_pAESContext.get(), iv);
- fxcrt::Copy(iv, dest);
+ auto dest_span = pdfium::make_span(dest);
+ fxcrt::Copy(iv, dest_span);
int nblocks = source.size() / 16;
- CRYPT_AESEncrypt(m_pAESContext.get(), dest.subspan(16).data(),
+ CRYPT_AESEncrypt(m_pAESContext.get(), dest_span.subspan(16).data(),
source.data(), nblocks * 16);
uint8_t padding[16];
fxcrt::Copy(source.subspan(nblocks * 16, source.size() % 16), padding);
fxcrt::Fill(pdfium::make_span(padding).subspan(source.size() % 16),
16 - source.size() % 16);
CRYPT_AESEncrypt(m_pAESContext.get(),
- dest.subspan(nblocks * 16 + 16).data(), padding, 16);
- return 32 + nblocks * 16;
+ dest_span.subspan(nblocks * 16 + 16).data(), padding, 16);
+ dest.resize(32 + nblocks * 16);
+ return dest;
}
- DCHECK_EQ(dest.size(), source.size());
- if (dest.data() != source.data()) {
- fxcrt::Copy(source, dest);
- }
+ CHECK_EQ(dest.size(), source.size());
+ fxcrt::Copy(source, dest);
CRYPT_ArcFourCryptBlock(dest, pdfium::make_span(realkey).first(realkeylen));
- return dest.size();
+ return dest;
}
struct AESCryptContext {
diff --git a/core/fpdfapi/parser/cpdf_crypto_handler.h b/core/fpdfapi/parser/cpdf_crypto_handler.h
index 0bddb1d..aef533d 100644
--- a/core/fpdfapi/parser/cpdf_crypto_handler.h
+++ b/core/fpdfapi/parser/cpdf_crypto_handler.h
@@ -16,6 +16,7 @@
#include "core/fdrm/fx_crypt.h"
#include "core/fxcrt/binary_buffer.h"
#include "core/fxcrt/bytestring.h"
+#include "core/fxcrt/data_vector.h"
#include "core/fxcrt/fx_memory_wrappers.h"
#include "core/fxcrt/retain_ptr.h"
#include "core/fxcrt/span.h"
@@ -38,17 +39,15 @@
~CPDF_CryptoHandler();
bool DecryptObjectTree(RetainPtr<CPDF_Object> object);
- size_t EncryptGetSize(pdfium::span<const uint8_t> source) const;
- // Returns number of valid bytes in `dest`.
- [[nodiscard]] size_t EncryptContent(uint32_t objnum,
- uint32_t gennum,
- pdfium::span<const uint8_t> source,
- pdfium::span<uint8_t> dest) const;
+ DataVector<uint8_t> EncryptContent(uint32_t objnum,
+ uint32_t gennum,
+ pdfium::span<const uint8_t> source) const;
bool IsCipherAES() const;
private:
+ size_t EncryptGetSize(pdfium::span<const uint8_t> source) const;
size_t DecryptGetSize(size_t src_size);
void* DecryptStart(uint32_t objnum, uint32_t gennum);
ByteString Decrypt(uint32_t objnum, uint32_t gennum, const ByteString& str);
diff --git a/core/fpdfapi/parser/cpdf_encryptor.cpp b/core/fpdfapi/parser/cpdf_encryptor.cpp
index 30e611f..dd1c555 100644
--- a/core/fpdfapi/parser/cpdf_encryptor.cpp
+++ b/core/fpdfapi/parser/cpdf_encryptor.cpp
@@ -22,11 +22,7 @@
if (src_data.empty()) {
return DataVector<uint8_t>();
}
- size_t estimated = m_pHandler->EncryptGetSize(src_data);
- DataVector<uint8_t> result(estimated);
- size_t actual = m_pHandler->EncryptContent(m_ObjNum, 0, src_data, result);
- result.resize(actual);
- return result;
+ return m_pHandler->EncryptContent(m_ObjNum, 0, src_data);
}
CPDF_Encryptor::~CPDF_Encryptor() = default;
